February 3, 2005, Pratt Conference Room at 12:30 pm

Precision Optical Time-Series Photometry for Thousands of Stars

Mr. Joel Hartman (CfA)

Since the advent of the microlensing surveys exploration of the time-domain has become an extremely active field in astronomy. Efforts are underway to survey the sky for microlensing events, transiting planets, supernovae and other cataclysmic events, variable stars, etc. In general, these surveys can be improved by extending the time baseline of the survey, increasing the number of relevant stars surveyed, or the area of sky coverage, and improving the photometric precision. In this talk I will describe two projects that I have participated in that center around precision time-series photometry for a large number of stars. The Hungarian Automated Telescope (HAT) project is a wide-field survey for transiting Hot Jupiters. I will describe our recent success at achieving millimagnitude precision for the bright stars in a highly crowded (over 100,000 stars), 8x8 square degree field, near the galactic plane, using image subtraction techniques. I will also describe current efforts to achieve sub-millimagnitude per minute precision for a number of open clusters using Megacam on the MMT, and the implications for a ground-based survey for transiting Hot Neptunes.